Amber Agate / Carnelian

Physical Properties

Hardness: 6.5-7 on Mohs scale. Color: Translucent orange, honey-yellow, or brownish-red. Luster: Waxy to vitreous. Crystal Structure: Trigonal (microcrystalline/cryptocrystalline). Cleavage: None (conchoidal fracture). Specific Gravity: 2.58-2.64.

Formation & Geological History

Formed through the deposition of silica from groundwater into cavities of igneous rocks, particularly volcanic lavas. Often found as river-worn nodules that have been tumbled naturally over thousands of years.

Uses & Applications

Used primarily for lapidary work, jewelry (beads, cabochons), and as aquarium stones or decorative landscaping. High-quality carnelian is prized in carving and seal-making.

Geological Facts

Carnelian and amber agate have been used by humans for over 5,000 years; ancient Romans and Egyptians used them for signet rings and amulets because wax does not stick to the smooth surface of the stone.

Field Identification & Locations

Identify in the field by its translucency when held to a light, its waxy texture, and the absence of visible grains. It is commonly found in gravel pits, riverbeds, and beaches, particularly in the Pacific Northwest (USA) or Brazil.

Identified on: 4/20/2026

Mode: Standard